Exemplary embodiments relate to a method of manufacturing non-volatile memory devices and, more particularly, to a method of forming trenches for isolation.
FIG. 1 is a photograph illustrating known features of a conventional non-volatile memory device.
As non-volatile memory devices are manufactured with a higher degree of integration, a stack layer GP for a gate has narrower width, but becomes higher.
The stack layer GP is formed by forming a plurality of stack layers, including a gate insulating layer, a conductive layer for floating gates, and a hard mask layer, over a semiconductor substrate and then patterning the stack layers. After the stack layers are formed, part of the semiconductor substrate exposed between the stack layers is etched to form trenches for isolation.
An etch process for forming the trenches for isolation is performed using a dry etch process. Here, fumes 10 may be formed because by-products generated during the dry etch process are stagnated. If a cleaning process for removing the fumes 10 is performed after the trenches are formed, it takes relatively long time to fully remove the fumes 10 stagnated while the trenches are formed, thereby increasing time of manufacturing a non-volatile memory device. In particular, since tension between a cleaning solution used in the cleaning process and the stack layers GP is increased, the stack layers GP may be inclined (refer to a photograph (A) of FIG. 1). If the stack layers GP are inclined, the yield of the non-volatile memory device is lowered because the adjacent stack layers GP may be interconnected. If a cleaning process is not performed for preventing the occurrence of this inclination phenomenon, the non-volatile memory device may be manufactured with defects at the portions where the fumes are generated as shown in a photograph (B) of FIG. 1, thereby reducing the yield.